With rapid development of farming and forestry, it is seriously desired to strengthen the inspection and quarantine of the imported logs and wood products to prevent spread of risky pests. Conventional quarantine treatment of the logs employs a method of fumigation by Methyl Bromide. This method has distinct shortcomings and limitations. Methyl Bromide would deplete the ozone layer of the atmosphere, and according to the amendment to “The Montreal Protocol on Substances that Deplete the Ozone Layer” at Copenhagen (1992), in order to protect the ozone layer of the atmosphere, each developed country of the parties of the Protocol shall ensure that for the twelve-month period commencing on Jan. 1, 2005 and in each twelve-month period thereafter, its calculated level of consumption of Methyl Bromide does not exceed zero, and, each developing country shall ensure that for the twelve-month period commencing on Jan. 1, 2015 and in each twelve-month period thereafter, its calculated level of consumption of Methyl Bromide does not exceed zero. Fumigation by Methyl Bromide is infeasible at a temperature below 5° C. Methyl Bromide is poisonous to nerve, and would be released to the atmosphere after the treatment of fumigation, contaminating the living environment of human being. Further, phytosanitary treatment by fumigation with Methyl Bromide is fairly inefficient because it needs over 16 hours to seal the logs to complete one treatment. Additionally, at some ports, particularly the ports of maritime transportation, the logs will be directly processed after being loaded onto the ground. Therefore it is infeasible to conduct the conventional quarantine treatment at the harbor districts with limited area.